1. Technical Field
The present invention relates to suspending and positioning metal reinforcing bars (rebar) in the footings and foundations of buildings and other structures.
2. Background Art
The use of rebar in reinforced concrete structures, and in particular, concrete structures in which the reinforcing steel has a connection with surrounding earth, is well known. The typical application is usually typified by the placement of rebar in the footings or foundations utilized in homes, commercial buildings, or other concrete structures. The long time practice for utilizing rebar in the construction of the footing or other foundational support system for building and the like is to dig a trench in the ground and, in order to impart tensile strength to the concrete which will fill the trench and constitute the footing, suspend one or more horizontally-positioned layers of steel reinforcing bars within the trench.
To impart the necessary tensile strength to the footing, these reinforcing bars, typically called xe2x80x9crebar,xe2x80x9d are usually laid at a height above the ground which is generally ⅓ to xc2xd the total resultant height of the concrete footing. For example, if a concrete footing is to be 12 inches in depth, the rebar would lie at a distance of approximately 3 to 5 inches from the bottom surface of the concrete, and thus 3 to 5 inches above the bottom of the dug trench. The common practice is to drive a vertical stake into the ground at the bottom of the trench, and then attach a row of horizontally-positioned rebar at the proper height using a piece of wire wrapped crossways around both the stake and the horizontally-positioned rebar.
In addition, it has been common practice to use a short piece of rebar as the vertical stake since it may be pounded easily into the ground, and provides the necessary strength to hold the horizontal rebar in place against the force of the concrete as it is poured around the horizontal rebar and the vertical stake.
Although the above-mentioned practices are convenient and well accepted in the construction industry, they are not without problems. One of the most significant issues is the amount of time that is required to place the rebar supports in place. Since the placement of the rebar is a manual process, it can be very time-consuming to place and tie each section of rebar in place. Additionally, the use of wire to tie the rebar in place can provide for less than optimal stability. In some cases, the wire is not tied securely and the weight of the concrete being poured over the horizontally-positioned rebar can cause the rebar to dislodge and move out of position. Alternatively, the rebar may shift or rotate in place, further destabilizing the rebar support system. If this happens, the structural integrity of the concrete foundation or structure can be comprised. Any such undesirable movement of the horizontally-positioned rebar requires an even more time-consuming operation to retrieve the horizontally-positioned rebar and replace it in the proper location. Accordingly, without an improvement in rebar support systems which provide an inexpensive, quick and easy installation process while also maintaining the requisite stability, the placement of rebar in foundations will continue to be sub-optimal.
According to the preferred embodiments of the present invention, an apparatus and method for suspending rebar is disclosed. The rebar isolator of the present invention comprises a pointed metal spike or stake with one or more hollow-bodied rebar supports. Each of the rebar supports has at least one support arm which supports the horizontally-positioned rebar. In addition, the spike or stake portion of the rebar isolator has a number of crimped zones which prevent the hollow-bodied rebar supports from shifting downward or rotating in place when the concrete is poured over the horizontally-positioned rebar. The number of crimped zones corresponds to the number of hollow-bodied rebar isolator supports and one crimped zone is located immediately below each of the support arms. One embodiment employs multiple rebar supports such that multiple pieces of rebar can be positioned in parallel, with each piece of rebar occupying space in substantially the same vertical plane as every other piece of rebar.